基于有源电子互感器的输电线路等传变差动保护  

Current differential relay of a transmission line based on an active electronic transformer using value after an equal transfer processes

作　　者：李宝伟[1,2] 文明浩 石欣[2] 戚宣威 张家琪 LI Baowei;WEN Minghao;SHI Xin;QI Xuanwei;ZHANG Jiaqi(State Key Laboratory of Advanced Electromagnetic Engineering and Technology,Huazhong University of Science and Technology,Wuhan 430074,China;XJ Electric Co.,Ltd.,Xuchang 461000,China;State Grid Zhejiang Electrical Power Research Institute,Hangzhou 310014,China;State Grid Corporation of China,Beijing 100031,China)

机构地区：[1]强电磁工程与新技术国家重点实验室(华中科技大学),湖北武汉430074 [2]许继电气股份有限公司,河南许昌461000 [3]国网浙江省电力有限公司电力科学研究院,浙江杭州310014 [4]国家电网有限公司,北京100031

出　　处：《电力系统保护与控制》2022年第21期157-166,共10页Power System Protection and Control

基　　金：国家自然科学基金项目资助(51877090)。

摘　　要：罗氏线圈电子式电流互感器的积分环节会放大传变误差,可能造成电流传变严重失真,导致保护误动。针对此问题,提出了线路保护直接采用罗氏线圈微分电流信号输出的改进思路。并以差动保护为例,提出了一种基于有源电子互感器的输电线路等传变差动保护方法。该方法直接采用罗氏线圈输出的电流微分信号进行计算,将用于电容电流补偿计算的电压信号经虚拟罗氏线圈数字传变处理,保证电压电流信号经过相同的传变环节。仿真和试验结果表明,新方法在区内故障时可快速动作,且消除了积分环节引入的传变误差对差动保护的影响,降低了电压电流传变差异对保护精度的影响,性能优于现有差动保护方法。The integrator of a Rogowski coil current transformer will amplify the error of current transfer and probably cause serious distortion of the current transfer.This will lead to protection mal-operation.To this end,an improved idea for a line relay directly using the differential current output of Rogowski coil is put forward.Taking the differential relay as an example,a current differential relay of the transmission line based on an active electronic transformer using value after equal transfer processes is proposed.In the scheme,the differential current output from the Rogowski coil is directly used for protection calculation,and the voltage signal used for capacitance current compensation calculation is transformed by a virtual Rogowski coil to ensure that the voltage and current signals have the same transfer process.Simulation and experimental results demonstrate that the novel relay has high operational speed in the case of internal faults,the influence of the transmission error introduced by the integral link is eliminated,the impacts of voltage and current signal transmission difference on protection accuracy are mitigated and the performance is superior to the existing differential protection methods.

关 键 词：罗氏线圈 积分器 电容电流补偿 虚拟数字罗氏线圈 差动保护 

分 类 号：TM452[电气工程—电器] TM773